June 2021
Installation, Operation and Maintenance Manual
MAN712 Rev. 9
Section 11: Restore Valve Control
Restore Valve Control
104
Section 11: Restore Valve Control
After the execution of the Safety Action (see Section 5.1.2.7), the ELBS-20 enters in the
Slow Sampling (SLOW) Operating Mode.
The ELBS-20 cannot initiate another Safety Action, if the Valve Control conditions are
not restored.
Two different procedures must be followed to restore the Valve Control, depending on the
selection of DO1 and/or DO2 as SOVs Controls Outputs.
Procedure without DO1 and DO2 selected as SOVs Control Outputs
In this case one or more outputs between SVC1, SVC2, RL1 and RL2 are set as SOVs
Control Output.
SVC1, SVC2, RL1 and RL2 initiate the Safety Action and after a settable time
(“Duration” parameter) return to their initial status so for restoring the Valve Control
the following steps must be followed:
•
Verify that the Safety Action is completely finished.
•
Move the pipeline valve from the “safe position” to the “normal position” by doing
all the necessary operations (ex. re-arm hand return valves).
•
Verify that the Pressure value, read by the ELBS-20, is between the “HP Limit” and
the “LP Limit” and stable (no drop of pressure).
•
Set the Operating Mode of the ELBS-20 as VC or VC + ACQ.
Procedure with DO1 and DO2 selected as SOVs Control Outputs
DO1 and DO2 when used as SOV Control Outputs (see Section 6.2), when the Safety
Action is finished, do not change their status but it is necessary to “manually” reset them.
The procedure below must be followed.
•
If DO1 is used as SOV Control Outputs, set the function of DO1 as “OFF” for
forcing its commutation.
•
If DO2 is used as SOV Control Outputs, set the function of DO2 as “OFF” for forcing
its commutation.
•
Move the pipeline valve from the “safe position” to the “normal position” by doing
all the necessary operations.
•
Verify that the Pressure value, read by the ELBS-20, is between the “HP Limit”
and the “LP Limit” and stable (no drop of pressure).
•
Set the Operating Mode of the ELBS-20 as VC or VC + ACQ.
•
If DO1 is used as SOV Control Outputs, restore the function of DO1 as
“SOV CONTROL”.
•
If DO2 is used as SOV Control Outputs, restore the function of DO2 as
“SOV CONTROL”.